How Rising Temperatures Threaten Brazil's Health System and Economy
Extreme heat is no longer just a weather anomaly; it's a public health emergency in the making. Our new study published in Environment International reveals the mounting toll that high temperatures are taking on Brazil’s health system, projecting a sharp increase in hospital admissions and economic losses by the 2050s if no action is taken.
Our research, conducted in collaboration with colleagues from the London School of Hygiene & Tropical Medicine (LSHTM), the International Institute for Applied Systems Analysis (IIASA), partners in Brazil, and University College London (UCL), is the first to comprehensively assess both the current and future impacts of high temperature on hospitalisations across Brazil. The findings are striking: without adaptation, annual heat-related hospitalisations are projected to rise by over 70% by the 2050s compared to the 2010s baseline, with economic costs expected to more than double, reaching over $260 million per year.
From Data to Insight: What We Did
This project started with one big question: How does extreme heat translate into real strain on hospitals and communities? To answer it, we analysed over a decade of hospital records from 5,459 municipalities across Brazil and combined them with climate data from global modelling scenarios. We used a robust statistical design to estimate how short-term exposure to high temperatures increases the risk of non-elective hospitalisations. We then projected these patterns into the future, considering multiple climate and demographic trajectories.
But hospital admission numbers alone wouldn’t tell the full story. To truly understand the broader impact, it was essential to estimate the costs. So our analysis went beyond just counting admissions. We estimated both the direct medical costs and the indirect economic burden (like lost productivity) linked to heat-related hospitalisations, under three different global warming scenarios.
Behind the Scenes: A Collaborative Effort
This research was not just a desk exercise; it relied on years of close teamwork across continents. Working from the UK, I teamed up closely with colleagues in Brazil to access hospital records covering more than 5,000 cities — no small task given the scale of data management and language barriers that we have to navigate.
One of our biggest challenges was matching this huge health dataset with credible climate projections for Brazil’s diverse regions. For months, our team worked across time zones to source reliable local climate data, refine our statistical models, and get the clearest possible picture from what was available.
Early on, it became clear that hospital figures alone wouldn’t be enough. We needed to show how heat ripples out into people’s livelihoods too. So we set out to estimate not just the direct medical costs, but the broader economic impact of lost productivity. Getting these numbers right took extra digging. At first, we used a simple rule of thumb — doubling the average hospital stay to estimate days off work. But our Brazilian collaborator Everton pointed out this wouldn’t reflect reality. He dug into municipal-level data on disease-specific absenteeism, making our productivity loss estimates much more reliable and more useful to local decision-makers.
Bringing together epidemiologists, statisticians, clinicians, and health economists gave this project its real depth. Every discussion brought new perspectives on how to handle tricky assumptions and local variations. That back-and-forth added months to our timeline, but made the final results much more credible and practical for policy.
In the end, this project reminded me that putting local evidence in front of a global audience takes more than data — it takes trust, patience, and collaboration. I hope these findings help inform Brazil’s climate adaptation plans and show how thoughtful, cross-border research can turn numbers into action.
Who Is Most at Risk?
The results show clear vulnerability patterns. Children and older adults are especially sensitive to heat, with significantly elevated risks of hospital admission for respiratory and kidney diseases. These impacts are not evenly distributed: the wealthier South, with lower natural heat acclimatisation, sees higher absolute health burdens, while the poorer North is experiencing the fastest rise in relative risks and per capita economic losses.
Adaptation Can Make a Difference
Even under a low-emission scenario, rising temperatures will continue to impact health through mid-century. But adaptation offers hope. If Brazilian regions adopt risk-reduction strategies—such as early warning systems, improved hospital infrastructure, and expanded urban cooling measures—our study suggests that mid-century economic losses could be reduced by up to 45%.
But there’s a catch. These optimistic scenarios rely on real political commitment, funding, and coordination across sectors. As Brazil prepares to host COP very soon, these findings are a timely reminder: mitigation is vital, but adaptation saves lives too.
Why This Matters for LMICs and Global Health
Brazil's unique combination of climate zones, healthcare data, and regional inequalities makes it a critical case study for other low- and middle-income countries. As the world warms, countries without strong adaptation strategies risk overwhelming their health systems and undermining economic development.
This study provides not just a warning, but a pathway: data-driven estimates of what lies ahead, and evidence that targeted investments can reduce future harms.
Looking Forward
This is the first national-scale projection of heat-related health and economic burdens in Brazil. Future research will refine adaptation modelling and explore the co-benefits of mitigation and resilience planning. As climate extremes become the norm, we must act not just to cut emissions, but to protect people from the very real health impacts of heat.
For me, this project reinforced a simple truth: behind every dataset are communities that deserve better answers and better protection. I hope our work helps local planners, national policymakers and global leaders take the bold, informed steps needed to build resilient, healthy futures — starting now.